1. Field of the Invention
The present invention relates to a valve assembly and timing device for fluid circulation systems, and more particularly, to an automatic valve assembly used in a wimming pool to control filtering and filter backwash flow by a single valve.
2. Description of Related Art
Filtration systems are common in the field in which debris in the fluid is collected in a filter such as a sand bed from the fluid, typically water, passing through the filter. The filtered water or fluid is returned to its source, such as a pool, reservoir, cooling system, reactor, or the like. It is also common to employ a means for reversing the flow through the filter to backwash-accumulated debris from the filter device or filter medium to a waste receptacle to remove the debris or waste from the filtering system. The present description will be directed to a filtration system for a swimming pool including means for backwashing the filtration system although it will be understood to those skilled in the art that the valve and method and apparatus of the invention can be used for other fluid control systems.
Known in the field are filtration systems having automatic filter backwash mechanisms which are mechanically operated and pressure driven. These devices may include an automatic timing feature to reset the valve after a backwash cycle. One such filtering system for use in irrigation devices, such as sprinklers, or sprayers, discloses a backwash process which includes a fluid operated timing device having a piston and a chamber. The timer is positioned in a port of a cylindrical filter housing. Other devices employ relatively large structures to provide the timing feature. A known device includes upper and lower tipping trays mounted above the filter having a pressure-operated valve which allows an upper tipping tray to fill. As the pressure exceeds the valve's preset operating pressure, the upper tray eventually tips downwardly operating a backwash valve. After the upper tray tips down, the lower tray tips up and begins to fill until it tips to the down position and restores the backwash valve to the original position. A disadvantage of this system is the relatively large and cumbersome design.
Also known in the art are backwash systems having a four-port valve body and a manually operated redirection plate. A disadvantage of a manually operated redirection plate is that it requires the supervision and intervention of a person to activate the backwash system. In the absence of human intervention for any number of reasons, the backwash system can remain un-activated resulting in clogging of the filtration system and/or dirty water being recycled to the swimming pool.
Known backwash systems may include a five-port valve body having a double-headed valve element and a rotary backwash plate. Typically, the double-headed valve element as well as the rotary backwash plate is actuated using a motor, or a motor-driven cam to move in its designed direction. Other backwash filter systems may use a double-headed valve element moved by mechanisms such as a fluid-operated piston requiring a power source. A disadvantage of these type that they are not automated, and require power be supplied and motor driven mechanisms to move the valve element. Thus, human intervention is required to activate the power, and the associated motor itself requires maintenance and repair. The expense to run these type systems, therefore, will be greater than an automated valve system which consumes little or no power or human intervention.
Bearing in mind the problems and deficiencies of the prior art, it is therefore an object of the present invention to provide an automatic valve apparatus which provides multiple ports for selectively directing fluids passing through the valve.
It is yet another object of the present invention to provide an automatic valve apparatus which uses a fluid pressure timing device and method for using the apparatus for timing the filtering and backwashing process.
An additional object of the present invention provides an automatic timing device which is preferably used in conjunction with the valve of the invention.
Another object of the present invention provides a filtration and backwash system.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.